Religion and science are not "separate magisteria" or anything of the sort. The failure of many scientists to realize this is generally because of compartmentalization, i.e. the idea that the scientific method and other related principles only apply in certain domains. In fact, they apply to all truth claims. (See http://lesswrong.com/lw/i8/religions_claim_to_be_nondisprovable/ and http://lesswrong.com/lw/gv/outside_the_laboratory/ for more thorough explanations of this, for starters.)

Let's be quantitative about how scientists differ in belief from the general population. We are many, many times more likely to be atheists, non-religious, or express doubts about religion than the general population. In the US, one estimate is that 30% of scientist are atheists, vs. maybe 2% of the general population who are atheists. 50% of scientists are without religious affiliation, vs. 16% of the general population. Only 36% of scientists state an explicit belief in God. See http://www.opposingviews.com/i/growing-number-of-scientists-are-atheists for more statistics (and note that the data was gathered by someone attempting to argue the opposite point, that scientists generally are religious.)

The idea that religion deserves "courtesy" is nonsense. No belief deserves protection from criticism. Also, "irrational" is a word with a specific meaning, not just a general insult.

As a side note, the entire paragraph I quoted contains only 2 periods. That is a serious barrier to readability.